<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <script>
      function fu(arr) {
        if (arr.length <= 1) return arr
        let max = 0 //最长时间
        let max1 = 0
        for (let i = 0; i < arr.length; i++) {
          if (i == 0 || i % 2 == 0) {
            max += arr[i]
          } else {
            max1 += arr[i]
          }
        }
        if (arr.length % 2 == 0 && arr[arr.length - 1] > arr[arr.length - 2]) {
          max = max - arr[arr.length - 2] + arr[arr.length - 1]
        }
        return max > max1 ? max : max1
      }
      console.log(fu([1, 2, 3, 4, 5, 7]))
    </script>
  </body>
</html>
